x86-64 disassembler support.

Change-Id: I0ae39ae1ffdae2500ff368354f9e4702445176f0
diff --git a/disassembler/disassembler.cc b/disassembler/disassembler.cc
index 5c17a83..41ee213 100644
--- a/disassembler/disassembler.cc
+++ b/disassembler/disassembler.cc
@@ -34,7 +34,9 @@
   } else if (instruction_set == kMips) {
     return new mips::DisassemblerMips();
   } else if (instruction_set == kX86) {
-    return new x86::DisassemblerX86();
+    return new x86::DisassemblerX86(false);
+  } else if (instruction_set == kX86_64) {
+    return new x86::DisassemblerX86(true);
   } else {
     UNIMPLEMENTED(FATAL) << "no disassembler for " << instruction_set;
     return NULL;